tgates

hi have a 91 z28 5.7tpi and im looking for anyones opinion about my car.
I just got back from the track and had PERFECT TRACTION and 75* air,
best time-
60'-1.8
1/8-8.5 @ 85mph
1/4-13.6 @ 95mph

my mods
full exhaust-shorty headers back, no cat or mufflers
full msd ignition
gutted air box W/ air foil and k&ns
FPR
upgraded injectors
3.73 gears
drag radials
2500 stall
TUNED- ebl f4 flash tuning computer
and some other smaller things

stock block, cam, heads and tpi intake

my question is, is my 1/4 time and mph seem off? I only picked up 10mph and ran a great 1/8th but only a 13.6 1/4. it seems to me that I should be a little faster than that.

(((I ran a 1/8th= 8.9 @ 76mph 1/4= 13.7 @ 98mph before my gears/stall/old computer with a chip/street tires/and stock exhaust w/ dumpoff.))) so after all that I gained only in my 60', and 1/8th mile? seems like I would see a much better 1/4 mile.

***I JUST BOUGHT A HSR MANIFOLD hoping to see the 1/4 mile gain I want.*** do you guys think this will help out???!!!

any and all inputs welcome!!!!

Gtpguy

Well my best time in my old bone stock L98/auto 3.27 GTA Was 14.8@94 with a mediocre 2.2 60ft. It was a cold az night, car was in good shape. The time you ran isn't bad at all for a stall and full exhaust. The trap seems low, considering I ran only 1mph slower without
Mods. But that could be traction and the stall taking up some trap speed.

Matts97camaro

First off that 13.7 @98 mph is very impressive with a stock TPI 5.7 motor besides the dump off . The elapsed time is right there with a good running stock M6 WS6 or SS LT1.. really you are almost in stock auto LS1 territory except for the mph. What is the track elevation?? Is it Atco? I had a chipped 89 GTA 5.7 that ran 14.9 @ 92 mph. Before the chip it ran 15.00-15.10 @90 mph. That was Atlanta Dragway which is 1100 elevation. I ran 13.9 @ 100 mph with a pretty much stock auto formula 95 LT1. All it had was a bigger y pipe and 160 stat.

Seems like your running good in the 1/8 mile but down 3 mph in the 1/4 after the mod. My only guess is now that your breathing better on the exhaust is the TPI is holding you back on the top end which is typical of the factory TPI intake.

popo8

My vettes best was a 14.99

MEMBER @ LTXtech.com

quickchicken

a few years back GMHTP did an article on 2 3gs, a couple of LT cars and a couple of LS cars. one of the 3rd gens only had suspension mods exhaust and a few other things and was all bone stock internally and hit a high 12, the other car had a pizza box and was a tad slower because the pizza box moves the RPM range up and pulls TQ out.

this is what will happen when you run with the HSR. the TPI creates gobs of TQ and that's what will net you a fast trap. i'll see if I can find the article and report back.

tom2

Times seem pretty decent to me, and I'd bet the car really felt strong. Fun.

Vincentiroc

You ran out of HP at 4800 with the 3.73 gears. If you had 3.42 gears you speed will be over 100. Try using a taller slick. What tire size slick are you using?

Doc87IROCZ

Yea, I think your 13.6sec ET is very impressive for a nearly stock L98. With cam and heads help, I went 12.97sec with my L98.